libsqfs: Implement exact matching of fragments

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 82 insertions, 1 deletions

diff --git a/lib/sqfs/block_processor/winpthread.c b/lib/sqfs/block_processor/winpthread.c
index c3e3d13..806c749 100644
--- a/lib/sqfs/block_processor/winpthread.c
+++ b/lib/sqfs/block_processor/winpthread.c
@@ -78,6 +78,8 @@ struct compress_worker_t {
 	thread_pool_processor_t *shared;
 	sqfs_compressor_t *cmp;
 	THREAD_HANDLE thread;
+	sqfs_u32 frag_blk_index;
+	sqfs_u32 frag_blk_size;
 	sqfs_u8 scratch[];
 };
 
@@ -178,6 +180,14 @@ static THREAD_TYPE worker_proc(THREAD_ARG arg)
 			store_completed_block(shared, blk, status);
 
 		blk = get_next_work_item(shared);
+
+		if (blk != NULL && (blk->flags & SQFS_BLK_FRAGMENT_BLOCK) &&
+		    shared->base.uncmp != NULL && shared->base.file != NULL) {
+			memcpy(worker->scratch + shared->base.max_block_size,
+			       blk->data, blk->size);
+			worker->frag_blk_index = blk->index;
+			worker->frag_blk_size = blk->size;
+		}
 		UNLOCK(&shared->mtx);
 
 		if (blk == NULL)
@@ -388,6 +398,70 @@ static int append_to_work_queue(sqfs_block_processor_t *proc,
 	return status;
 }
 
+static sqfs_block_t *find_frag_blk_in_queue(sqfs_block_t *q, sqfs_u32 index)
+{
+	while (q != NULL) {
+		if ((q->flags & SQFS_BLK_FRAGMENT_BLOCK) && q->index == index)
+			break;
+		q = q->next;
+	}
+	return q;
+}
+
+static int compare_frag_in_flight(sqfs_block_processor_t *proc,
+				  sqfs_block_t *frag, sqfs_u32 index,
+				  sqfs_u32 offset)
+{
+	thread_pool_processor_t *thproc = (thread_pool_processor_t *)proc;
+	sqfs_block_t *it = NULL;
+	void *blockbuf = NULL;
+	size_t i, size = 0;
+	int ret;
+
+	if (proc->frag_block != NULL && proc->frag_block->index == index)
+		it = proc->frag_block;
+
+	if (it == NULL)
+		it = find_frag_blk_in_queue(thproc->proc_queue, index);
+
+	if (it == NULL)
+		it = find_frag_blk_in_queue(thproc->io_queue, index);
+
+	if (it == NULL)
+		it = find_frag_blk_in_queue(thproc->done, index);
+
+	if (it == NULL) {
+		for (i = 0; i < thproc->num_workers; ++i) {
+			if (thproc->workers[i]->frag_blk_index == index) {
+				size = thproc->workers[i]->frag_blk_size;
+				blockbuf = thproc->workers[i]->scratch +
+					proc->max_block_size;
+				break;
+			}
+		}
+	} else if (it->flags & SQFS_BLK_IS_COMPRESSED) {
+		proc->buffered_index = 0xFFFFFFFF;
+		blockbuf = proc->frag_buffer;
+		ret = proc->uncmp->do_block(proc->uncmp, it->data, it->size,
+					    blockbuf, proc->max_block_size);
+		if (ret <= 0)
+			return -1;
+		proc->buffered_index = it->index;
+		size = ret;
+	} else {
+		blockbuf = it->data;
+		size = it->size;
+	}
+
+	if (blockbuf == NULL || size == 0)
+		return -1;
+
+	if (offset >= size || frag->size > (size - offset))
+		return -1;
+
+	return memcmp((const char *)blockbuf + offset, frag->data, frag->size);
+}
+
 static int block_processor_sync(sqfs_block_processor_t *proc)
 {
 	return append_to_work_queue(proc, NULL);
@@ -398,6 +472,7 @@ int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
 {
 	thread_pool_processor_t *proc;
 	unsigned int i, num_workers;
+	size_t scratch_size;
 	sigset_t oldset;
 	int ret;
 
@@ -419,6 +494,7 @@ int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
 
 	proc->base.sync = block_processor_sync;
 	proc->base.append_to_work_queue = append_to_work_queue;
+	proc->base.compare_frag_in_flight = compare_frag_in_flight;
 	proc->num_workers = num_workers;
 	proc->max_backlog = desc->max_backlog;
 	((sqfs_object_t *)proc)->destroy = block_processor_destroy;
@@ -430,8 +506,12 @@ int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
 	SIGNAL_DISABLE(&oldset);
 
 	for (i = 0; i < num_workers; ++i) {
+		scratch_size = desc->max_block_size;
+		if (desc->uncmp != NULL && desc->file != NULL)
+			scratch_size *= 2;
+
 		proc->workers[i] = alloc_flex(sizeof(compress_worker_t),
-					      1, desc->max_block_size);
+					      1, scratch_size);
 
 		if (proc->workers[i] == NULL) {
 			ret = SQFS_ERROR_ALLOC;
@@ -440,6 +520,7 @@ int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
 
 		proc->workers[i]->shared = proc;
 		proc->workers[i]->cmp = sqfs_copy(desc->cmp);
+		proc->workers[i]->frag_blk_index = 0xFFFFFFFF;
 
 		if (proc->workers[i]->cmp == NULL) {
 			ret = SQFS_ERROR_ALLOC;